Extrapyramidal Diseases

Diseases of the extrapyramidal system present a broad range of movement disorders including disorders of muscle tone, posture and gait, paucity of movements, and

FIGURE 5.22

Sporadic adult onset bulbospinal muscular atrophy. A 58-year-old man gave a 3-year history of difficulty swallowing and 50-pound weight loss over the past 2 years. On admission, he appeared emaciated, with severe generalized muscle wasting, especially of the small hand muscles. Fasciculations were noted in the arm and neck muscles. Reflexes were hypoactive, and the plantar responses were flexor. Sensation was normal. The speech was hoarse. He died suddenly of hemorrhagic bronchopneumonia. Family history was negative for neuromuscular diseases. A. The hand shows atrophy of the small intrinsic muscles. B. Medulla shows neuronal losses in the hypoglossus nucleus. C. Cervical cord shows losses of motor neurons (LFB-CV stain).

FIGURE 5.22

Sporadic adult onset bulbospinal muscular atrophy. A 58-year-old man gave a 3-year history of difficulty swallowing and 50-pound weight loss over the past 2 years. On admission, he appeared emaciated, with severe generalized muscle wasting, especially of the small hand muscles. Fasciculations were noted in the arm and neck muscles. Reflexes were hypoactive, and the plantar responses were flexor. Sensation was normal. The speech was hoarse. He died suddenly of hemorrhagic bronchopneumonia. Family history was negative for neuromuscular diseases. A. The hand shows atrophy of the small intrinsic muscles. B. Medulla shows neuronal losses in the hypoglossus nucleus. C. Cervical cord shows losses of motor neurons (LFB-CV stain).

abnormal involuntary movements. The movement disorders are often associated with behavioral changes, mood disorder, hallucinations, cognitive decline, and dementia. Dementia of extrapyramidal diseases is often referred to as subcortical dementia, to distinguish it from dementia of cortical origin. In contrast to cortical dementia, which manifests with impairments of memory, language, and other cognitive functions and learned motor skills, subcortical dementia manifests with slowness of thinking and concept formation, impairment of executive functions, forgetfulness, apathy, indifference, and depression. The features of cortical and subcortical dementias may occur together. These diseases chiefly affect adults in their fifth and sixth decades. The course is slowly progressive, ranging from 2 to 15 or 20 years. The majority of cases are sporadic, but some are inherited.

The principal sites of neuronal degeneration are the basal ganglia, midbrain, and brainstem. The cerebral cortex is involved, but to a lesser extent. The presence of distinct neuronal and glial cytoplasmic inclusions is characteristic.

The two major forms of extrapyramidal diseases are those presenting primarily with akinetic rigidity and those presenting primarily with abnormal involuntary movements (Table 5.10).

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